A need has long existed in the concrete construction industry for a practical, efficient and convenient column or beam form which is reusable and economical to manufacture and laborsaving.
The prior art has contained some proposals to satisfy this need, and a typical example of the patented prior art is U.S. Pat. No. 3,107,087 issued to C. I. Williams on Oct. 15, 1963. In general, known or proposed devices for this purpose have not been adopted to any significant degree commercially for the simple reason that none has proven to be sufficiently convenient and fool-proof to use particularly by unskilled construction workers, and hence the need for a satisfactory knock-down reusable column or beam form has not been satisfied.
Accordingly, it is the objective of this invention to totally satisfy the above need of the art through the provision of a separable and reusable concrete construction form which is economical to manufacture, extremely durable and long-lasting, easy to assemble by unskilled labor and, in this sense, substantially fool-proof since it cannot be assembled improperly. Among the important features and advantages of the invention over the prior art are the self-squaring ability of the assembled form, its resistance to grout leakage at the corners due to a tight and uniform fit of the components and a superior resistance to bulging or buckling under heavy fluid-induced internal pressure. It is realistically estimated that the customary time involved in the construction of conventional forms on the job site can be reduced by fifty per cent. A great deal of plywood and other material waste is eliminated by the reusable nature of the form. The components of the invention are lightweight and strong and the panels are easily carried and set up in single, double or triple side combinations.
Other features and advantages of the invention will become apparent during the course of the following description.